diff --git a/Compras/PopUpVerFactura.aspx.vb b/Compras/PopUpVerFactura.aspx.vb
index 99cd97ad1..1eaa7301e 100644
--- a/Compras/PopUpVerFactura.aspx.vb
+++ b/Compras/PopUpVerFactura.aspx.vb
@@ -910,7 +910,7 @@ Partial Class PopUpVerFactura
             If Archivo.Exists Then
                 HttpContext.Current.Response.Clear()
                 HttpContext.Current.Response.ClearContent()
-                HttpContext.Current.Response.ContentType = If(IO.Path.GetExtension(Archivo.Name) = "xml", "application/xml", "application/pdf")
+                HttpContext.Current.Response.ContentType = If(IO.Path.GetExtension(Archivo.Name).ToLower = "xml", "application/xml", "application/pdf")
                 HttpContext.Current.Response.AppendHeader("Content-disposition", String.Format("attachment; filename={0}", Archivo.Name))
                 HttpContext.Current.Response.AddHeader("Content-Length", Archivo.Length.ToString())
                 HttpContext.Current.Response.TransmitFile(Path)